Method of preventing decomposition of halogenated hydrocarbons



Patented Aug. 18,1931

UNITED STATES PATENT OFFICE EDWARD c. zUcKERMANpEL, or MIDLAND, MICHIGAN, ASSIGNOR TO THE DOW CHEMICAL COMPANY, or MIDLAND, MICHIGAN, A CORPORATION or MICHIGAN METHOD OF PREVENTING DECOMPOSITION OF HALOGENA'IED HYDROCARBONS No Drawing.

'- The present invent-ion relates to the prevention of the decomposition of halogenated aliphatic hydrocarbons by means of the addition thereto of certain substances which,

when present in only relativelysmall amount,

have the property of inhibiting such decomposition. Moreparticularly, it is concerned with the preservation of chlorinated, or brominated, derivatives of methane, ethane, and ethylene, which have a tendency to decompose under the combined influence of air, moisture, heat or light, or a combination of such factors, with the formation of phosgene, C001 and hydrochloric acid, or the corresponding bromide derivatives. Examples of such compounds are carbon tetrachloride, C01 chloroform, CHCl trichlorethylene, CIZHCL, tetrachlorethylene, C 01 and the li e.

It is known that the addition to chloroform of absolute alcohol in amount of about two per cent. assists in preventing decomposition. Other substances, such as parafiin oil (purified liquid petrolatum) petroleum ether, etc.,

have been suggested and are said to be eifecfor the purpose described are comprised in the group .of oil-soluble dyes which are well known and used as dyestuffs under Various trade names. Examples of such are sold under the trade name of Oil Red 0, Oil Orange 2311 and Oil Scarlet 6G. The dyes named are azo compounds, having the following described constitution:

Oil Red O, diazotized amino-azo-ben- 5o zene coupled with beta-'naphthol.

1 Application filed 3, 1928. Serial No. 297,368.

Oil Orange 2311, diazotized aniline coupled with beta-naphthol. Oil Scarlet 6G, diazotized xylidine coupled Witlr beta-naphthol.

Other oil-soluble dyesthat give good results are known as Oil Blue MG, and Oil Green M255, but I have not determined theconstitution of these dyes. As small an amount of one of the dyes just mentioned as one part per million, dissolve in the halogenated hydrocarbon, will delay decomposition of the latter for a period of several weeks. Preferably, however, I dissolve the dye in the halogenated hydrocarbon, e. g., any one of the compounds hereinbefore specifically named, or the like, in the proportion of one part in 10,000. In this amount it has been found to "prevent decomposition indefinitely. The invention is not limited to the examples given, which are introduced merely b Way of illustration, nor to the addition of suc mentioned dye to halogenated aliphatic hydrocarbons in the amounts specified, as it is evident that numerous modifications from a the procedure described may be introduced without departing from the principle and scope of the invention. c.

This method of preserving has been found to have not only the advantages of cheapness and ease of application along with attainment ofpreservative results,but I have found that the color imparted to the so treated halogenated hydrocarbon gives it a deslrable quality for 'certain uses in the arts.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the method herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

I therefore particularly point out and distinctly claim as my invention:-

1. The herein described method of pie venting the decomposition of halogenated aliphatic hydrocarbons which consists in adding thereto in relatively small. amount an oil-soluble, azo dye containing component.

2. The herein described method of prea phenolic w venting the decomposition of halogenated aliphatic hydrocarbons which consists in adding thereto in relatively small amount an oil-soluble azo dye containing betanaphthol as one component.

3. The herein described method of preventing the decomposition of chlorinated aliphatic hydrocarbons which consists in adding thereto a relatively small amount of an oil-soluble azo dye containing a phenolic component. 1

4. The herein described method of preventing the decomposition of chlorinated aliphatic hydrocarbons which consists in adding thereto in relatively small amount an oil-soluble azo dye containing betanaphthol as one component.

5. As a composition of matter'ahalogenated aliphatic hydrocarbon containing a relatively small amount of an oil-soluble azo dye dissolved therein, said dye including a phenolic component.

6. As a composition of matter a halogenated' aliphatic hydrocarbon containing a relatively small amount of an oil-soluble azo dye dissolved therein, said dye including betanaphthol as one component.

relatively small amount of xylene-azo-betw naphthol dissolved therein.

16. As a compositionof matter a chlorincontaining a relatively small amount of benzene-azo-beta-naphthol dissolved therein. 21. As a composition of matter chloroform containing a relatively small amount of xylene-azo-beta-naphthol dissolved therein. Signed by me this 31st day of July, 1928.

EDlVARD C. ZUCKERMANDEL.

7. As a composition of matter a chlorin ated aliphatic hydrocarbon containing 'a relatively small amount of an oil-soluble azo dye dissolved therein, said dye'including a phenolic component. i

8. As a composition of matter a chlorinated aliphatic hydrocarbon containing a relatively small amount of an oil-soluble azo dye dissolved therein, said dye including betanaphthol as one component.

9. The herein described method of preventing the decomposition of halogenated aliphatic hydrocarbons which consists in. adding thereto azo'benzene-azo-betanaphtholin relatively small amount. 10. The herein described method of preventing-the decomposition of chlorinated aliphatic hydrocarbons which consists in adding thereto azobenzene-azo-betanaphtholin relatively small amount.

11. As a composition of matter, a haloge- I nated aliphatic hydrocarbon containing a relatively small amount of .azobenzene-azobetanaphthol dissolved therein.

12. As a composition of matter, a chlorinated aliphatic hydrocarbon containingfa relatively small amount of azobenzene-azobetanaphthol dissolved therein.

13. As a composition of matter a halogenated aliphatic hydrocarbon containing a rel- I atively small amount of benzeneazo-betanaphthol dissolved therein.

' 14. As a composition of matter a chlorinated aliphatic hydrocarbon containing a relatively small amount of benzene-azo-betanaphthol dissolved therein.

'15."As a composition of matter-ahalogenated aliphatic hydrocarbon containing a 

